Washing of clothes by hand or in semi-automatic machines is widespread in many countries; seventy percent of the world's population still wash their clothes in this way. When doing so, consumers usually like to see a lot of lather (foam) as they associate foaming with detergent efficiency. However, removing the lather requires numerous rinses, generally three or more rinses, which costs a lot of effort and wastes water.
Most foam control agents are designed for use in automatic washing machines. They are active in the washing stage to avoid overflow of foam. They are less suitable for hand washing applications as they eliminate or greatly reduce the lather in the washing stage. A foam control agent that would not greatly reduce the foam level in the washing stage but would cause fast defoaming in the rinse would allow saving of significant quantities of water and reduce the time and efforts needed for rinsing.
According to the present inventive concepts, a new antifoam has been devised which is active in diluted surfactant concentration and which is inactive in concentrated surfactant solution. It will be appreciated that the main difference between the washing stage and the rinse stage of a wash process is the surfactant concentration.